The theory now is that, once the patch update has been applied, iPhone's bars will report signal strength "far more accurately" providing users a better indication of the reception in a given area.

I thought the problem was more like calls being disconnected because of signal reception. That is, the iPhone4 fails in locations that other phones don't. They are just saying like, we are going to fix the graphics it so that you are aware you have a inferior product

The problem is that the addition of a rubber "bumper" apparently fixes the signal interference. From what I've read it seems that the hand is causing interference because it is touching both sides of the aerial.

I'm not an RF Engineer but even I know that touching an aerial changes the reception, sometimes better but more likely to be worse. Whose bright idea was it to make the body of the iPhone the aerial?